The use of identification documents is pervasive. Identification documents are used on a daily basis—to prove identity, to verify age, to access a secure area, to evidence driving privileges, to cash a check, and so on. Airplane passengers are required to show an identification document during check in, and sometimes at security screening and prior to boarding their flight. We also live in an ever-evolving cashless society. Identification documents are used to make payments, access an automated teller machine (ATM), debit an account, or make a payment, etc. Many industries require that their employees carry photo ID on the job.
For the purposes of this disclosure, identification documents are broadly defined and may include, e.g., credit cards, bank cards, phone cards, passports, driver's licenses, network access cards, employee badges, debit cards, security cards, visas, immigration documentation, national ID cards, citizenship cards, social security cards, security badges, certificates, identification cards or documents, voter registration cards, police ID cards, border crossing cards, legal instruments or documentation, security clearance badges and cards, gun permits, gift certificates or cards, labels or product packaging, membership cards or badges, etc., etc. Also, the terms “document,” “card,” and “documentation” are used interchangeably throughout this patent document. Identification documents are also sometimes interchangeably referred to as “security documents,” “ID documents,” “photo-IDs” and “photo ID documents”.
With reference to FIG. 1, an identification document 10 includes a “card-shaped” substrate 21, historically made from a material such as paper or plastic, but now even made from synthetics such as Teslin®. (Teslin® is available from PPG Industries, One PPG Place, Pittsburgh, Pa. 15272 USA). Identification document 10 includes a photograph 14 and various data 12, e.g., such as textual information, graphics, a screened-back or hidden image, bar codes, biometric information (e.g., a fingerprint), text information (e.g., name, address, birth date, ID number, etc.), or the like. Of course both sides of substrate 21 can receive printing or engraving. Other suitably interchangeable features and materials are found, e.g., in assignee's U.S. patent application Ser. No. 10/330,032, filed Dec. 24, 2002 (published as US 2003-0173406 A1), which is herein incorporated by reference.
The printed substrate 21 is usually laminated. The laminate typically includes a plastic, polyester or polycarbonate-based top sheet 23 and bottom sheet 25 that respectively overlay the top and bottom of the substrate 21. Heat and/or adhesives and pressure are used to bond the laminate sheets 23 and 25 with the substrate 21. Or a laminate can include a pouch into which the substrate 21 slips. Again, heat and/or adhesives and pressure are used to bond the substrate 21 with a pouch laminate. The laminates provide a protective covering for the printed substrate and provide a level of protection against unauthorized tampering. (For example, a laminate would have to be removed to alter the printed information and then subsequently replaced after the alteration). A laminate layer 23 or 25 may optionally carry information like a card bearer's signature or security features.
In some implementations, information may also be optically or magnetically stored on recording media (e.g., magnetic stripe 27, or optical memory or electronic circuitry—not shown in FIG. 1) carried by the laminate 25. Of course the recording media can be alternatively carried by substrate 21 or laminate 23.
We note that the present invention encompasses ID documents including more or less features and layers than are illustrated in FIG. 1. Additional features may include graphics printed in dual color optically variable ink, microprinting text, so-called “ghost images,” information and images printed in UV inks, and security features such as those disclosed in, e.g., assignee's U.S. patent application Ser. No. 10/170,223 (published as US 2003-0031340 A1), which is herein incorporated by reference.
Identification documents can also include information such as a bar code (e.g., which may contain information specific to the person whose image appears in the photographic image, and/or information that is the same from ID document to ID document), variable personal information (e.g., such as an address, signature, and/or birth date, biometric information associated with the person whose image appears in the photographic image, e.g., a fingerprint), a magnetic stripe (which, for example, can be on the a side of the ID document that is opposite a side with a photographic image), and various security features (e.g., a security pattern like a printed pattern comprising a tightly printed pattern of finely divided printed and unprinted areas in close proximity to each other, such as a fine-line printed security pattern as is used in the printing of banknote paper, stock certificates, and the like). Of course, an identification document can include more or less features.
Another example of an identification document is one including a core layer (which can be pre-printed), such as a light-colored, opaque material, e.g., TESLIN, which is available from PPG Industries) or polyvinyl chloride (PVC) material. The core can be laminated with a transparent material, such as clear PVC to form a so-called “card blank”. Information, such as variable personal information (e.g., photographic information, address, name, document number, etc.), is printed on the card blank using a method such as Dye Diffusion Thermal Transfer (“D2T2”) printing (e.g., as described in commonly assigned U.S. Pat. No. 6,066,594, which is herein incorporated by reference), laser or ink jet printing, offset printing, etc. The information can, for example, comprise an indicium or indicia, such as the invariant or nonvarying information common to a large number of identification documents, for example the name and logo of the organization issuing the documents. Any known process capable of forming the indicium may be used to form the information.
To protect the information that is printed, an additional layer of transparent overlaminate can be coupled to the card blank and printed information, as is known by those skilled in the art. Illustrative examples of usable materials for overlaminates include biaxially oriented polyester or other optically clear durable plastic film.
Of course, there are many other identification documents that include different structures, features and materials. These other identification documents can be suitably interchanged with the identification documents described herein. The inventive digital watermarking techniques disclosed herein will similarly benefit these other documents as well.
An identification document may include a digital watermark. Digital watermarking is a process for modifying physical or electronic media to embed a machine-readable code into the media. The media may be modified such that the embedded code is imperceptible or nearly imperceptible to the user, yet may be detected through an automated detection process. In some of our preferred embodiments, an identification document includes two or more digital watermarks.
Digital watermarking systems typically have two primary components: an encoder that embeds the digital watermark in a host media signal, and a decoder that detects and reads the embedded digital watermark from a signal suspected of containing a digital watermark (a suspect signal). The encoder embeds a digital watermark by altering the host media signal. The alterations usually take the form of altered signal values, such as slightly changed pixel values, luminance, colors, changed DCT coefficients, altered signal values or selective placement or signal tweaks, etc. However, a watermark can also be manifested in other ways, such as changes in the surface microtopology of a medium, localized chemical changes (e.g. in photographic emulsions), localized variations in optical density, localized changes in luminescence, etc. The surface texture of an object may be altered to create a watermark pattern. This may be accomplished by manufacturing an object in a manner that creates a textured surface or by applying material to the surface (e.g., an invisible film or ink) in a subsequent process. The watermark reading component analyzes content to detect whether a watermark pattern is present. In applications where the watermark encodes information, the reading component extracts this information from the detected watermark. The reading component analyzes a suspect signal to detect whether a digital watermark is present. The reading component can be hosted on a wide variety of units ranging from tethered or wireless reader devices, conventional personal computers, network servers, cell phones including cameras, to fully mobile readers with built-in displays. Image data corresponding to a watermarked surface of an identification document is read and decoded by this reader to obtain a watermark's information or “payload”.
Several particular digital watermarking techniques have been developed. The reader is presumed to be familiar with the literature in this field. Some techniques for embedding and detecting imperceptible watermarks in media signals are detailed in assignee's U.S. Pat. No. 6,614,914, U.S. Pat. No. 6,122,403 and PCT patent application PCT/US02/20832 (published in English as WO 03/005291), which are each herein incorporated by reference.
In assignee's U.S. Pat. No. 5,841,886 techniques and methods are disclosed to detect alteration of photo ID documents, and to generally enhance the confidence and security of such systems. In this regard, reference is made to FIG. 2, which depicts a photo-ID card or document 1000 which may be, for example, a passport or visa, driver's license, credit card, government employee identification, or a private industry identification badge. For convenience, such photograph-based identification documents will be collectively referred to as photo ID documents.
The photo ID document includes a photograph 1010 that is attached to the document 1000. Printed, human-readable information 1012 is incorporated in the document 1000, adjacent to the photograph 1010. Machine-readable information, such as that known as “bar code” may also be included adjacent to the photograph. Generally, the photo ID document is constructed so that tampering with the document (for example, swapping the original photograph with another) should cause noticeable damage to the card. Nevertheless, skilled forgers are able to either alter existing documents or manufacture fraudulent photo ID documents in a manner that is extremely difficult to detect. Security associated with the use of photo ID documents is enhanced by supplementing the photographic image with encoded information (which information may or may not be visually perceptible), thereby facilitating the correlation of the photographic image with other information concerning the person, such as the printed information 1012 appearing on the document 1000.
A photograph 1010 may be produced from a raw digital image to which is added a master snowy image as described in U.S. Pat. No. 5,841,886. A central network and point-of-sale reading device (which device, in the present embodiment, may be considered as a point-of-entry or point-of-security photo ID reading device), would essentially carry out the same processing as described with that embodiment, including the central network generation of unique numbers to serve as indices to a set of defined orthogonal patterns, the associated dot product operation carried out by the reader, and the comparison with a similar operation carried out by the central network. If the numbers generated from the dot product operation carried out by the reader and the central network match, in this embodiment, the network sends the OK to the reader, indicating a legitimate or unaltered photo ID document.
It will be appreciated that the information encoded into the photograph may correlate to, or be redundant with, the readable information 1012 appearing on the document. Accordingly, such a document could be authenticated by placing the photo ID document on a scanning system, such as would be available at a passport or visa control point. The local computer, which may be provided with the universal code for extracting the identification information, displays the extracted information on the local computer screen so that the operator is able to confirm the correlation between the encoded information and the readable information 1012 carried on the document. It will be appreciated that the information encoded with the photograph need not necessarily correlate with other information on an identification document. For example, the scanning system may need only to confirm the existence of the identification code so that the user may be provided with a “go” or “no go” indication of whether the photograph has been tampered with. It will also be appreciated that the local computer, using an encrypted digital communications line, could send a packet of information to a central verification facility, which thereafter returns an encrypted “go” or “no go” indication.
In another implementation of the '886 patent, it is contemplated that the identification code embedded in the photograph may be a robust digital image of biometric data, such as a fingerprint of the card bearer, which image, after scanning and display, may be employed for comparison with the actual fingerprint of the bearer in very high security access points where on-the-spot fingerprint recognition systems (or retinal scans, etc.) are employed.
We disclose herein methods, systems and identification document to improve or provide alternative techniques for confronting fraudulent use of identification documents. Fraudulent use of identification documents may occur where, for example, an otherwise legitimate identification document is modified such that the original photograph is swapped with that of another person, thereby enabling the other person to masquerade, at least temporarily, under the guise of the original identification document holder.
Even in the absence of photo swapping or alteration, it is oftentimes difficult to confirm by inspection that the individual depicted in the photograph of the identification card is indeed the bearer of the card.
One aspect of this invention provides enhanced security and certainty in the use of photo identification documents.
Another aspect provides methods and systems for authenticating and securing identification documents using multiple digital watermarks or multiple watermark components.
According to still another aspect of the present invention, a security document includes a substrate and a first graphic carried by the substrate. The first graphic conveys a photographic image to human viewers thereof, and the first graphic is steganographically encoded to convey first plural bits of data recoverable by computer analysis of the first graphic. The security document also includes a second graphic carried by the substrate. The second graphic conveys a visual image to human viewers thereof, and the second graphic is steganographically encoded to convey second plural bits of data recoverable by computer analysis of said second graphic. The steganographically encoded first plural bits of data and the steganographically encoded second plural bits of data cooperate to verify authenticity of the security document.
According to still another aspect of the invention, a method is provided to detect swapping of first artwork from a first identification document with second artwork on a second identification document. The swapping results in the first artwork being carried on the second identification document instead of the second artwork. The first artwork includes a first digital watermark embedded therein, and the second identification document includes a second digital watermark embedded in a first region. The method includes: receiving scan data associated with at least a portion of the first artwork and at least a portion of the first region; analyzing the scan data to detect the first digital watermark and the second digital watermark; and comparing the first digital watermark with the second digital watermark to detect swapping of the first artwork with the second artwork.
Another aspect of the present invention is a security document including a substrate and a first graphic carried by the substrate. The first graphic conveys a photographic image to human viewers thereof, and the first graphic is steganographically encoded to convey first plural bits of digital data recoverable by computer analysis of said first graphic. The security document also includes a second graphic, the second graphic conveying a visual image to human viewers thereof. The security document also includes a detection trigger. The detection trigger serves to indicate a presence of steganographic encoding. The second graphic is steganographically encoded to convey second plural bits of digital data recoverable by computer analysis of said second graphic, wherein the steganographically encoded first plural bits of digital data and the steganographically encoded second plural bits of digital data cooperate to verify authenticity of the security document.
Still another aspect of the present invention is a method of identifying a first area and a second area of a printed document that are likely to include, respectively, a first digital watermark and a second digital watermark. The first digital watermark includes a first orientation component and the second digital watermark includes a second orientation component. The method includes receiving optically scanned image data that corresponds with at least a portion of the printed document; segmenting the image data into a plurality of image portions; determining an orientation measure relative to a predetermined orientation for each of the image portions; identifying the first area by associating image portions having a first orientation measure; and identifying the second area by associating image portions having a second orientation measure.
Additional features, aspects and advantages of the present invention will become even more apparent with reference to the following detailed description, accompanying drawings and claims.